Enzyme-containing detergent compositions for neutral washing

ABSTRACT

ENZYME-CONTAINING DETERGENT COMPOSITIONS ESPECIALLY ADAPTED TO LAUNDRY APPLICATIONS UNDER NEUTRAL AND NEARNEUTRAL CONDITIONS OF PH ARE DISCLOSED. THE DETERGENT COMPOSITIONS CONSIST ESSENTIALLY OF A SYNTHETIC ORGANIC DETERGENT CHARACTERIZED BY SOLUBILITY IN WATER OF AT LEAST 0.05% AT A TEMPERATURE OF ABOUT 80*F. TO ABOUT 130* F. EFFICIENT SOIL-REMOVING AND SOIL-DISPERSING PROPERTIES IN WATER IN AN AMOUNT OF ABOUT 0.05% AND RESISTANCE TO PRECIPITATION BY HARD WATER MINERAL IONS; 0.001% TO 5% OF A PROTEOLYTIC ENZYME CHARACTERIZED BY PROTEOLYTIC ACTIVITY UP TO ABOUT 130*F. IN THE PH RANGE OF 6 TO 8.5; AND A PHOSPHORUS-CONTAINING COMPOUND HAVING SUFFICIENT CALCIUM SEQUESTRATION PROPERTIES TO REDUCE THE CALCIUM ION CONCENTRATION OF AN AQUEOUS SOLUTION CONTAINING 1.2X10**-3 M OF CALCIUM ION TO A CONCENTRATION OF 1.7X10**-4 M OR LESS WHEN EMPLOYED IN AN AMOUNT OF UP TO 0.1% OF THE SOLUTION. THE COMPOSITIONS OF THE INVENTION HAVE A PH OF FROM 6 TO 8.5 IN AQUEOUS SOLUTION AT A CONCENTRATION OF 0.12%.

United States Patent 3,658,727 ENZYME-CONTAINING DETERGENT COMPOSI- TIONS FOR NEUTRAL WASHING Roy C. Mast, Colerain Township, Hamilton County, Ohio,

assignor to The Procter & Gamble Company, Cincinnati, Ohio No Drawing. Filed May 2, 1969, Ser. No. 821,471 Int. Cl. Clld 3/065, 1/12 U.S. Cl. 252-538 7 Claims ABSTRACT OF DISCLOSURE Enzyme-containing detergent compositions especially adapted to laundry applications under neutral and nearneutral conditions of pH are disclosed. The detergent compositions consist essentially of a synthetic organic detergent characterized by solubility in water of at least 0.05 at a temperature of about 80 F. to about 130 F. eflicient soil-removing and soil-dispersing properties in water in an amount of about 0.05% and resistance to precipitation by hard water mineral ions; 0.001% to 5% of a proteolytic enzyme characterized by proteolytic activity up to about 130 F. in the pH range of 6 to 8.5; and a phosphorus-containing compound having sufficient calcium sequestration properties to reduce the calcium ion concentration of an aqueous solution containing 1.2 10 M of calcium ion to a concentration of 1.7 X 10 M or less when employed in an amount of up to 0.1% of the solution. The compositions of the invention have a pH of from 6 to 8.5 in aqueous solution at a concentration of 0.12%.

This invention relates to cleansing and laundering compositions particularly adapted to use under neutral or near-neutral conditions of pH. More particularly, it relates to neutral or near-neutral detergent compositions containing a detegent active, a proteolytic enzyme and a phosphorus-containing sequestrant compound. These compositions provide superior levels of cleaning and whitening heretofore unattainable under the neutral or near-neutral washing conditions hereinafter defined.

The use of enzymes in admixture with detergent compositions is known and is described, for example, in U.S. Pat. 1,882,279 issued Oct. 11, 1932. Similarly, British Pat. 814,772 issued June 10, 1959, East German Pat. 14,296 published Jan. 6, 1958 and Jaag in Seifen, Ole, Fette, Wachse 88, No. 24, pp. 789793 (November 1962) disclose enzyme-containing detergent compositions. Proteolytic enzymes aid the cleaning process by degrading or otherwise altering proteinaceous soils and rendering them more easily removable by the detersive action of a detergent compound. In addition, their degradative action serves to digest or break down proteinaceons materials which serve as binding agents for nondigestible soils.

Various attempts have been made in the art to formulate enzyme-containing detergent compositions containing an enzyme material having compatibility with synthetic detergents and appreciable soiland stain-removing efficacy. While it has been known that proteolytic enzymes often exhibit their peak enzymatic activity under neutral conditions of pH, these attempts have often involved the formulation of enzyme-containing compositions containing an appreciable amount of inorganic components to render alkaline the washing solutions prepared therefrom. The preparation of highly alkaline enzyme-containing detergent compositions has evolved at .least in part from the belief that synthetic detergents function most effectively in terms of soil removal under alkaline conditions. While these highly alkaline enzymecontaining detergent compositions provide high levels of cleaning, including efiicient stain-removing properties, the washing of laundry under neutral or near-neutral conditions of pH is attendant with certain decided advantages over washing under the alkaline conditions of pH normally encountered in the use of conventional, heavy-duty laundry detergent formulations.

One advantage of neutral or near-neutral washing is the substantial avoidance of the formation and precipitation of insoluble salts or complexes normally encountered under alkaline conditions, e.g. at about pH 9 or greater, by the reaction of metal ions in wash water, e.g., calcium ions, with the fatty acid components of lipid soils. The washing of textile materials under neutral or nearneutral conditions greatly minimizes the formation of these scum deposits which contribute to an overall poor appearance of laundered materials. Moreover, it eliminates the need for scum dispersers conventionally employed in the art to alleviate the problems inherent in the formation of such deposits.

Another advantage to neutral or near-neutral washing is the elimination of the formation of mineral deposits by the reaction of alkaline components normally encountered in heavy-duty laundering compositions with the metal ions present in the washing solution. These deposited inorganic metal salts weaken the laundered fabrics, particularly at those areas of the fabric which are exposed to frictional and creasing effects, such as collars and cuffs, resulting in a loss of useful life and impart harshness or poor hand to the laundered fa'brics. In addition to these advantages, the employment of neutral or near-neutral washing compositions in the cleansing of textile materials, greatly reduces the corro sion of metal parts in washing machines frequently encountered in connection with the employment of Washing solutions characterized by high alkalinity.

While neutral or near-neutral washing conditions are to be preferred from many standpoints, the cleaning levels attainable in the laundering of textile materials have not been entirely satisfactory and have generally been in- .ferior to those attainable by laundering textile materials under the conditions of alkalinity normally attendant the use of conventional heavy-duty built anionic detergent formulations.

OBJECTS OF THE lNVENTION It is an object of the present invention to provide detergent compositions having superior cleansing and laundering properties.

It is another object of the present invention to provide cleansing and laundering compositions effective in the attainment of superior levels of cleaning under neutral or near-neutral washing conditions.

It is a further object of the invention to provide substantially neutral enzyme-containing detergent compositions exhibiting superior soiland stain-removing properties.

Other objects of the present invention will become apparent from a consideration of the invention which is described in detail hereinafter.

SUMMARY OF THE INVENTION This invention is based on the discovery that detergent compositions having a substantially neutral pH and comprising a proteolytic enzyme and certain critical detergent and phosphorus-containing components permit the attainment of superior levels of cleaning attained heretofore only with alkaline detergent compositions. The invention thus involves the preparation of substantially neutral laundry detergent compositions consisting essentially of a combination of essential components. These compositions consist essentially of:

(A) From 10% to 85% of a synthetic organic detergent characterized by:

(1) Solubility in water in a concentration of at least about 0.05% at a temperature of about 80 F. to about 130 F.;

(2) Efiicient soil-removing and soil-dispersing properties in a concentration of about 0.05 in water; and

(3) Resistance to precipitation by hard water mineral ions; and

(B) From 0.001% to 5% of a proteolytic enzyme characterized by proteolytic activity up to about 130 in the pH range of from 6 to 8.5; and

(C) From 10% to 75% of a phosphorus-containing sequestrant compound having suflicient calcium sequestration properties to reduce the calcium ion concentration of an aqueous solution containing 1.2 10* M of calcium ion to a concentration of 1.7 X 10- M or less when employed in an amount of up to 0.1% of the solution; and have a pH of from 6 to 8.5 in aqueous solution at a concentration of 0.12%.

DETAILED DESCRIPTION OF THE INVENTION The organic detergents which find applicability in the preparation of detergent formulations effective in neutral or near-neutral laundering include certain anionic, nonionic, zwitterionic and ampholytic detergents and mixtures thereof. The detergent compounds utilizable in the formulation of enzyme-containing detergent compounds of the invention are compounds which possess certain desirable properties. These properties include superior detergency and dispersancy and relative resistance to precipitation or insoluble complex formation under the conditions of pH and water hardness contemplated herein as neutral or near-neutral washing.

As employed herein, the terms neutral or near-neutral (hereinafter termed substantially neutral) washing conditions or compositions contemplate washing conditions or compositions which correspond to pHs in the range of 6 to 8.5. The terms detergency and dispersancy where employed herein refer, respectively, to the capacity to remove particulate and lipid soils from a substrate and the capacity to keep in suspension in a washing solution the particulate and lipid soils removed from a substrate by detersive action. Detergent and dispersant compounds utilizable herein must, in addition, perform satisfactorily in washing solutions containing hard water mineral ions normally present in tap water, e.g., without forming a precipitate or non-detergent insoluble complex. Where a detergent and dispersant material forms such a precipitate or insoluble-complex with hard water ions, the material is rendered into a relatively useless form and thereby does not function in its intended manner.

It has been found quite unexpectedly that superior levels of cleaning and whitening which heretofore have been attainable only under alkaline laundering conditions can be attained by employing a substantially neutral detergent composition which consists essentially of a synthetic organic detergent having the hereinbefore described properties in combination with a proteolytic enzyme material and a phosphorus-containing sequestrant compound.

The synthetic organic detergent compounds utilizable herein and having the hereinbefore described properties include certain anionic, semi-polar nonionic, ampholytic and zwitterionic materials. These materials include watersoluble salts of certain materials such as sulfonated fatty acid esters of p-acyloxyalkane-l-sulfonic acids; water-soluble alkyl ether sulfates; water-soluble olefin sulfonates; tertiary phosphine oxides; and certain ampholytic and zwitterionic detergents. Of the organic detergents investigated, only highly eifective detergents more specifically described hereinafter have been found in the compositions of the present invention to permit, under substantially neutral conditions, the attainment of levels of cleaning III . c c 0R2 wherein R is alkyl or alkenyl of about 10 to about 20 carbon atoms (forming with the two carbon atoms a fatty acid group); R is alkyl of 1 to about 10 carbon atoms; and M is a salt-forming radical.

The salt-forming radical M in the hereinbefore described structural formula is a water-solubilizing cation and can be, for example, an alkali metal cation (e.g., sodium, potassium, lithium), ammonium or substituted ammonium cation. Specific examples of substituted ammonium cations include methyl-, dimethyl-, and trimethyl-ammonium cations and quaternary ammonium cations such as tetramethyl ammonium and dimethyl piperidinium cations and those derived from alkylamines such as ethylamine, 1rgiethylamine, triethylamine, mixtures thereof and the Specific examples of this class of compounds include the sodium and potassium salts of esters where R is selected from methyl, ethyl, propyl, butyl, hexyl and octyl groups and the fatty acid group (R plus the two carbon atoms in the structure above) is selected from lauric, my-

ristic, palmitic, ste'aric, palmitoleic, oleic, linoleic acids and mixtures thereof. A preferred ester material herein is the sodium salt of the methyl ester of a-sulfonated tallow fatty acid, the term tallow indicating a carbon chain distribution approximately as follows: (E -2.5%, C 28%, C 23%, palmitoleic2%, oleic-4l.5%, and linoleic3% (the first three fatty acids listed are saturated).

Other examples of suitable salts of u-sulfonated fatty esters utilizable herein include the ammonium and tetramethylammonium salts of the hexyl, octyl, ethyl, and butyl esters of a-sulfonated tridecanoic acid; the potassium and sodium salts of the ethyl, butyl, hexyl, octyl, and decyl esters of m-sulfonated pentadecanoic acid; and the sodium and potassium salts of butyl, hexyl, octyl, and decyl esters of a-sulfonated heptadecanoic acid; and the lithium and ammonium salts of butyl, hexyl, octyl, and decyl esters of m-sulfonated nonadecanoic acid. The salts of a-sulfonated fatty acid esters of the present invention are known compounds and are described in US. Pat. 3,223,645, issued Dec. 14, 1965 to Kalberg, this patent being hereby incorporated by reference.

Another class of suitable anionic organic detergents includes salts of 2-acyloxy-alkane-l-sulfonic acids. These salts have the formula 0 ll ,oca

R1 cu 'CH2SO3M where R is alkyl of about 9 to about 23 carbon atoms (forming with the two carbon atoms an alkane group); R is alkyl of 1 to about 8 carbon atoms; and M is a saltforming radical hereinbefore described.

Specific examples of B-acyloxy-alkane-l-sulfonates, or alternatively 2-acyloxy-alkane-l-sulfonates, utilizable herein to provide superior cleaning levels under substantially neutral washing conditions include the sodium salt of Z-acetoxy-tridecane-l-sulfonic acid; the potassium salt of 2-propionyloxy-tetradecane-l-sulfonic acid; the lithium salt of 2-butanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of 2-pentanoyloxy-pentadecane-l-sulfonic acid; the ammonium salt of 2-hexanoyloxy-hexadecanc-l-sulfonic acid; the sodium salt of 2-acetoxy-hexadecane-l-sulfonic acid; the dimethylammonium salt of 2-heptanoyloxy-tridecane-l-sulfonic acid; the potassium salt of 2-octanoyloxy-tetradecane-l-sulfonic acid; the dimethylpiperidinium salt of 2-nonanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of Z-acetoxy-heptadecane-l-sulfonic acid; the lithium salt of 2-acetoxy-octadecane-l-sulfonic acid; the dimethylamine salt of Z-acetoxyoctadecane-l-sulfonic acid; the potassium salt of 2-acet0xy-nonadecane-l-sulfonic acid; the sodium salt of 2-acetoxy-uucosane-l-sulfonic acid; the sodium salt of 2-propionyloxy docosane-1-sul- -fonic acid; and isomers thereof.

Preferred fl-acyloxy-alkane-l-sulfonate salts herein are the alkali metal salts of fl-acetoxy-alkane-1-sulfonic acids corresponding to the above formula wherein R is an alkyl of about 12 to about 16 carbon atoms, these salts being preferred from the standpoints of their excellent cleaning properties and ready availability.

Typical examples of the above described B-acetoxy alkanesulfonates are described in the literature: Belgian Pat. 650,323 issued July 9, 1963, discloses the preparation of certain 2-acyloxy alkanesulfonic acids. Similarly, U.S. Pats. 2,094,451 issued Sept. 28, 1937, to Guenther et al. and 2,086,215 issued July 6, 1937 to De Groote disclose certain salts of fl-acetoxy alkanesulfonic acids. These references are hereby incorporated by reference.

Other synthetic anionic detergents useful herein are alkyl ether sulfates. These materials have the formula RO(C H O) SO M wherein R is alkyl or alkenyl of about 10 to about 20 carbon atoms, x is 1 to 30, and M is a salt-forming cation defined hereinbefore.

The alkyl ether sulfates of the present invention are condensation products of ethylene oxide and monohydric alcohols having about 10 to about 20 carbon atoms. Preferably, R has 14 to 18 carbon atoms. The alcohols can be derived from fats, e.g. coconut oil or tallow, or can be synthetic. Lauryl alcohol and straight chain alcohols derived from tallow are preferred herein. Such alcohols are reacted with 1 to 30, and especially 6, molar proportions of ethylene oxide and the resulting mixture of molecular species, having, for example, an average of 6 moles of ethylene oxide per mole of alcohol, is sulfated and neutralized.

Specific examples of alkyl ether sulfates of the present invention are sodium coconut alkyl ethylene glycol ether sulfate; lithium tallow alkyl trialkylene glycol ether sulfate; sodium tallow alkyl hexaoxyethylene sulfate; and ammonium tetradecyl octaox'yethylene sulfate.

Preferred herein for reasons of excellent cleaning properties and ready availability are the alkali metal coconutand tallow-alkyl oxyethyleue ether sulfates having an average of about 4 to about 10 oxyethyleue moieties. The alkyl ether sulfates of the present invention are known compounds and are described in U.S. Pat. 3,322,876 to Walker (July 25, 1967) incorporated herein by reference.

Other suitable anionic detergents utilizable herein are olefin sulfonates having about 12 to about 24 carbon atoms. The term olefin sulfonates is used herein to mean compounds which can be produced by the sulfonation of a-olefins by means of uncomplexed sulfur trioxide, followed by neutralization of the acid reaction mixture in conditions such that any sultones which have been formed in the reaction are hydrolyzed to give the corresponding hydroxy-alkanesulfonates. The sulfur trioxide may be liquid or gaseous, and is usually, but not neces sarily, diluted by inert diluents, for example by liquid S chlorinated hydrocarbon, etc., when used in the liquid form, or by air, nitrogen, gaseous S0 etc., when used in the gaseous form.

The a-olefins from which the olefin sulfonates are derived are mono-olefins having 12 to 24 carbon atoms,

6 preferably 14 to 16 carbon atoms. Preferably, they are straight chain olefins. Examples of suitable l-olefins include l-dodecene; l-tetradecene; l-hexadecene; l-octadecene; l-eicosene and l-tetracosene.

In addition to the true alkene sulfonates and a proportion of hydroxy-alkanesulfonates, the olefin sulfonates can contain minor amounts of other materials, such as alkene disulfonates depending upon the reaction conditions, proportions of reactants, the nature of the starting olefins and impurities in the olefin stock and side reactions during the sulfonation process.

A preferred embodiment is the use herein of olefin sulfonates which are described completely in U.S. Pat. 3,332,880 issued July 25, 1967, to Kessler et al., hereby incorporated by reference.

The nonionic detergents useful in the present invention are semi-polar detergent compounds and include, for example, long chain tertiary phosphine oxides having the structure wherein R is alkyl, alkenyl, or monohydroxyalkyl of about 8 to about 18 carbon atoms having from 0 to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety and R and R are each alkyl or monohydroxyalkyl groups containing from 1 to about 3 carbon atoms. The arrow in the formula is a conventional representation of the semi-polar bond.

Examples of suitable phosphine oxides are:

dodecyldimethylphosphine oxide, tetradecyldimethylphosphine oxide, tetradecylrnethylethylphosphine oxide, 3,6,9-trioxaoctadecyldimethylphosphine oxide, cetyldimethylphosphine oxide, 3-dodecoxy-2-hydroxypropyldi(2-hydroxyethyl)-phosphine oxide stearyldimethylphosphine oxide, cetylethylpropylphosphine oxide, oleyldiethylphosphine oxide, dodecyldiethylphosphine oxide, tetradecyldiethylphosphine oxide, dodecyldipropylphosphine oxide, dodecyldi(hydroxymethyl)phosphine oxide, dodecyldi(2-hydroxyethyl)phosphine oxide, tetradecylmethyl-2-hydroxypropyl phosphine oxide, ole'yldimethylphosphine oxide, and Z-hydroxydodecyldimethylphosphine oxide.

Ampholytic synthetic detergents utilizable herein can be broadly described as derivatives of aliphatic secondary and tertiary amines in which the aliphatic radical can be straight chain or branched and wherein one of the aliphatic substituents contains from about 8 to about 18 carbon atoms and one contains an anionic Water solubilizing group, e.g., cabroxy, sulfonate, sulfate, phosphate, or phosphonate. These detergents have the formula a -u-cu -a -zn wherein R is alkyl of about 8 to 18 carbon atoms, R is alkyl of l to about 3 carbon atoms or is hydrogen, R is alkylene of 1 to about 4 carbon atoms, Z is carboxy, sulfonate, sulfate, phosphate or phosphonate and M is a salt-forming cation. Examples of compounds falling within this definition are sodium 3-dodecylaminopropio nate; sodium 3-dodecylaminopropane sulfonate; N-alkyltaurines such as the ones prepared by reacting dodecylamine with sodium isethionate according to the teaching of U.S. Pat. 2,658,072; sodium salts of N-higher alkyl aspartic acids such as those produced according to the teaching of U.S. Pat. 2,438,091; and the products sold under the trade name Miranol and described in US. Pat. 2,528,378.

Zwitterionic synthetic detergents of the present invention can be broadly described as derivatives of aliphatic quaternary ammonium, phosphonium, and sulfonium compounds, in which the aliphatic radicals can be straight chain or branched, and wherein one of the aliphatic substituents contains from about 8 to 18 carbon atoms and one :contains an anionic water solubilizing group, e.g., carboxy, sulfonate, sulfate, phosphate, or phosphonate. A general formula for these compounds is:

R1 Y ca a z wherein R contains an alkyl, alkenyl, or hydroxyalkyl radical of from about 8 to about 18 carbon atoms having from to about 10 ethylene oxide moieties and from 0 to 1 glyceryl moiety; Y is selected from the group consisting of nitrogen, phosphorus, and sulfur atoms; R is an alkyl or monohydroxy alkyl group containing 1 to about 3 carbon atoms; x is 1 when Y is a sulfur atom and 2 when Y is a nitrogen or phosphorous atom, R is an alkylene or hydroxy alkylene of from 1 to about 4 carbon atoms and Z is a radical selected from the group consisting of carboxylate, sulfonate, sulfate, phosphonate, and phosphate groups.

Examples include:

4 [N,N-di Z-hydroxyethyl) -N-octadecyl-ammonio] butanel-c arboxylate;

5- S-3-hydroxypropyl-S-hexadecylsulfonio] -3- hydroxypentanel-sulfate;

3- [P,P-diethyl-P-3 6,9-trioxatetracos anephosphonio] -2- hydroxypropanel-phosphate;

3- [N,N-dipropyl-N-3 -dodecoxy-Z-hydroxypropylammonio] -propane-1-phosphonate;

3 N,N-dimethyl-N-hexadecylammonio) propane-1- sulfonate;

3 (N,N-dimethyl-N-hexadecyl-ammonio) -2- hydroxypropane-l-sulfonate;

4- [N,N-di Z-hydroxyethyl -N- (Z-hydroxydodecyl) ammonio] -butanel-carb oxyl ate;

3 [S-ethyl-S- (3-do decoxy-2-hydroxypropyl) sulfonio] prop anel-phosphate;

3- [P,P-dimethyl-P-dodecylphosphonio] -propane- 1- phosphonate; and

S- [N,N-di 3-hydroxypropy1) -N-hexadecylammonio] -2- hydroxypentane-l -sulfate.

Examples of compounds falling within this definition are 3 (N,N-dimethyl-N-hexadecyl-ammonio)propane-l-sulfonate and 3 (N,N dimethyl-N-hexadecyl-ammonio)-2- hydroxypropane-l-sulfonate which are especially preferred for their excellent cool water detergency characteristics.

The alkyl groups contained in said detergent surfactants can be straight or branched preferably straight and saturated or unsaturated as desired.

The detergent compounds of the present invention are employed in varying amounts in the enzyme-containing detergent compositions of the present invention. As there will be considerable variation in the strengths of washing solutions employed by different users, i.e., some users may tend to use more or less than others, the requisite amount of detergent compound in the detergent formulation is an amount sufficient to provide superior cleaning and whitening levels under diverse conditions of soiling and usage. The enzyme-containing detergent compositions of the present invention can contain by weight from to 85% of the synthetic organic detergent. A preferred amount of detergent is from to 50%.

The enzymes of this invention are solid catalytically active protein materials which degrade or alter one or more types of soil or stains encountered in laundering situations so as to remove the soil or stain from the fabric or object being laundered or make the soil or stain more removable in a subsequent laundering step. Both degradation and alteration improve soil removability. As used herein, enzyme activity refers to the ability of an enzyme to perform the desired function of soil attack and enzyme stability refers to the ability of an enzyme to remain in an active state.

The enzymatic components utilizable herein are those which exhibit their degradative and/or altering effects on proteinaceous soils and stains under the substantially neutral washing conditions contemplated herein, i.e., those which exhibit their proteolytic activity in aqueous solutions at pHs ranging from 6 to 8.5 and at temperatures of about 50 F. to about 130 F.

While applicant does not wish to be bound by any particular theory or mechanism, it is believed the proteolytic enzymes of the present invention catalyze the hydrolysis of the peptide linkage of proteins, polypeptides and related compounds to free amino and carboxyl groups and thus breakdown the protein structure in soil. Suitable proteolytic enzymes for use herein include those materials which are termed in the art neutral proteases. These materials exhibit the peak of their proteolytic activity in the substantially neutral range of pH contemplated herein. Also utilizable herein are proteolytic enzymes known in the art as alkaline proteases. While these materials exhibit their peak enzymatic effects in slightly alkaline solutions, their activity is still sufficient in the substantially neutral regions of pH as to render practicable their applicability herein. Preferred herein are proteolytic enzymes which exhibit their peak or substantial enzymatic activity in the substantially neutral regions hereinbefore defined.

The amount of proteolytic enzyme employed herein to provide the detergent compositions of the present invention is not critical and is an amount of proteolytic enzyme capable of effecting the degradation of the proteinaceous matter normally encountered in a home laundering situation under the washing conditions contemplated herein, e.g., at temperatures of about 50 F. to 130 F. and at pHs of from 6 to 8.5. Normally, the proteolytic enzyme is employed in an amount of about 0.001 to 5% by weight of the enzyme-containing detergent composition on a pure enzyme basis. Best results in terms of overall cleaning eflicacy and stain-removing properties are attained when the proteolytic enzyme is employed in an amount of about 0.01 to about 1%.

The above described proteases can be utilized in a pure form in the preparation of enzyme-containing detergent compositions. Generally, however, powdered commercial enzyme compositions containing these enzymes are utilized herein inasmuch as these compositions are easier to handle and retain their activity for a longer period of time. These commercial compositions contain about 2% to about active neutral and alkaline proteases in combination with inert powdered materials which comprise the remaining 20% to 98%. These powdered materials can comprise inorganic alkali metal salts 'such as sodium sulfate, sodium chloride, potassium silicate, sodium phosphate, inorganic alkaline earth metal salts such as calcium sulfate, magnesium sulfate, magneslum phosphate and the like; organic components such as non-enzymatic proteins, carbohydrates, organic clays, starches, lipids, color bodies, mixtures thereof and the like. Active enzyme content of a commercial product is a result of manufacturing methods employed and is not critical herein so long as the finished compositions have desired enzymatic soil and stain-removing properties.

The enzymes per so have molecular diameters of from about 30 angstroms to several thousand angstroms. However, the particle diameters of the anzyme powder as utilized herein are normally much larger due to agglomeration of individual enzyme molecules or addition of inert powdered materials or such as starch, organic clays, sodium or calcium sulfate or sodium chloride during enzyme manufacture. Enzymes are recovered from bacteria grown in solution. The powdered materials or vehicles are added after filtration of such solution to precipitate the enzyme in fine form which is then dried; calcium salts also stabilize some enzymes. The enzyme powders of this invention, including those employed in the examples, are typically fine enough to pass through a Tyler standard 20 mesh screen (0.85 mm.) although larger agglomerate's are often found. Some particles of commercially available enzyme powders are fine enough to pass through a Tyler standard 100 mesh screen. Generally a major amount of particles will remain on a 150 mesh screen. Thus, the powdered enzymes utilized herein usually range in size from about 1 mm. to 1 micron, most generally from 1 mm. to 0.01 mm. The enzyme powders of the examples have particle size distributions in these ranges.

The activity of the proteases of the present invention can be readily expressed in terms of activity units, e.g., casein assay activity units. In accordance with the casein assay method of determining proteolytic activity, a solution of the protease to be evaluated is allowed to digest by hydrolysis, a solution of casein substrate at an appropriate pH and temperature. The reaction is stopped by the addition of trichloroacetic acid, the solution is filtered and the color of the filtrate containing the digested casein is developed employing Folin-Ciocalteu phenol reagent. The degree of enzymatic activity is determined by comparing the 'spectrophotornetric response with that of solutions of varying concentrations of reagent grade tyrosin and determining the amount of tyrosine produced. The casein assay method of determining proteolytic activity is well known and a more detailed discussion is found in B. Hagihara et al., J. Biochem. (Tokyo), 45, 185 (1958) and M. Kunitz, J. Gen. Physiol., 291 (1947).

The activities of the proteases of the present invention vary depending largely upon the concentration of neutral and alkaline proteases in the enzymatic composition, upon calcium ion concentration, upon substrate concentration, and upon pH. Pure samples of proteases of the present invention are highly active. For example, a Bacillus subtilis-derived Carlsberg subtilisin employed herein is characterized by a protrease activity unit number on a pure basis of about 7,500,000 units/gram. Commercially available compositions wherein the protease is present in varying amounts with inert filler material or vehicle vary in activity from about 100,000 to about 1,500,000 units/ gram. Similarly, an X-ray mutated Bacillus subtilisderived subtilisin employed herein is characterized by an activity of about 7,500,000 units/gram, on a pure basis, while the commercial preparations vary in activity from about 100,000 to about 1,500,000 units/gram.

As described hereinbefore, the amount of protease employed herein in the enzyme-containing detergent compositions of the present invention is about 0.001 to about 5% of the composition on a pure enzyme basis. This amount corresponds to the incorporation into the detergent composition of about 75 to about 375,000 protease activity units/ gram of detergent composition. When a commercially available enzyme preparation is employed as described hereinbefore, from about 0.03% to about of the preparation is utilized. Preferably, from 0.1% to 5% is employed and provides excellent soiland stain-degrading properties. It will of course be appreciated that the amount of enzymatic composition required in the formulation of detergent compositions having a desired level of proteolytic activity varies with the activity level of the enzyme-containing composition employed. The precise amounts of such materials employed in the formulation of enzyme-containing detergent compositions can be readily determined by methods known in the art.

Specific examples of proteases suitable for use in this invention are trypsin, collagenase, keratinase, elastase, subtilisin, BPN and BPN'. Preferred proteases are serine proteases which are active in the substantially neutral pH ranges defined herein and are produced from microorganisms such as bacteria, fungi or mold. The serine pro- 10 teases which are procured by mammalian systems, e.g., pancreatin, are useful herein.

Preferred proteolytic enzymes herein are those derived from the bacterial organism Bacillus subtilis and termed subtilisins. These materials are preferred from the standpoints of excellent soiland stain-removing properties and ready availability. Also preferred are those proteases derived from the Streptomyces class of microoragnisms.

A preferred subtilisin of the present invention is the Bacillus subtilis-derived Carlsberg strain. The Carlsberg strain employed in accordance with the present invention is a known subtilisin strain, the amino acid sequence of which is described in Smith et al., The Complete Amino Acid Sequence of Two Types of Subtilisin, BPN and Carlsberg, J. of Biol. Chem., volume 241, Dec. 25, 1966 at page 5974. This subtilisin strain is characterized by a tyrosine to tryptophan ratio of about 13:1. The above reference including its description of the amino acid sequence of the Carlsberg subtilisin is hereby incorporated by reference.

An X-ray mutated Bacillus subtilis-derived subtilisin constitutes another preferred subtilisin of the present invention. This mutation can be effected in accordance with US. Pat. 3,031,380 issued Apr. 24, 1962 to Minagawa et al. by irradiation of a Bacillus subtilis organism with X-rays. Subsequent treatment in a conventional manner can be employed to result in the preparation of an enzymatic composition US. 3,031,380 describes a process whereby an enzymatic composition is produced by subjecting Bacillus subtilis to X-rays of an intensity corresponding substantially to 24-50 roentgens for an interval of at least half an hour, selecting from the colony thus subjected to X-rays a strain identified by cells having hairless, rough, jagged, spotted and dull white characteristics, sep arating said strain and placing the separated strain in a culture selected from the group consisting of wheat bran and corn meal, maintaining the culture for a period of at least 40 hours while aerating the culture substantially continuously, and drying the culture. The disclosure of US. Pat. 3,031,380 is hereby incorporated by reference.

Specific examples of commercial enzyme products and the manufacturer thereof include: Alcalase, Novo Industri, Copenhagen, Denmark; Maxatase, Koninklijke Nederlandsche Gist-En Spiritusfabriek N.V., Delft, Netherlands; Protease B-4000 and Protease AP, Schweizerische Ferment A.G., Basel, Switzerland; CRD-Protease, Monsanto Company, St. Louis, Mo.; Viokase, Vio- Bin Corporation, Monticello, Ill.; Pronase-P, Pronase-E, Pronase-AS and Pronase-AF all of which are manufactured by Kaken Chemical Company, Japan; Rapidase P- 2000, Rapidase, Seclin, France; Takamine, HT proteolytic enzyme 200, Enzyme-L-W (derived from fungi rather than bacteria), Miles Chemical Company, Elkhart, Ind.; Rhozyme P11 concentrate, Rhozyme PF, Rhozyme J-25, Rohrn & Haas, Philadelphia, Pa.; Rhozyme PF and J-25 have salt and corn starch vehicles and are proteases having diastase activity; amprozyme 200, Jacques Wolf & Company, a subsidairy of Nopco Chemical Company, Newark, N.J.; Takeda Fungal Alkaline Protease, Takeda Chemical Industries, Ltd., Osaka, Japan; Wallerstein 201- HA, Wallerstein Company, Staten Island, N.Y.; Protin AS-20, Dawai Kasei K.K., Osaka, Japan; and Protease TP (derived from thermophilic Streptomyces species strain 1689), Central Research Institute of Kikkoman Shoya, Noda Chiba, Japan.

Protease T P, its properties and characteristics, as well as methods for its preparation are described in Agr. Biol. Chem., 28, No. 12, pp. 884-895, December, 1964: Studies on the proteolytic Enzymes of Thermophilic Streptomyces, Part I. Purification and Some Properties; Agr. Biol. Chem., 30, No. 1, pp. 35-41, January 1966: Studies on the Proteolytic Enzymes of Thermophilic Strepto myces, Part II. Identification of the Organism and Some Conditions of Protease Formation; and Applied Micro- 1 1 biology, 17, No. 3, March 1969. The authors are Mizusawa et a1.

CRD Protease (also known as Monsanto DA-lO) is a useful powdered enzyme product. CRD-Protease is re ported to be obtained by mutation of a Bacillus subtilis organism. Its proteolytic enzyme is about 80% neutral protease and 20% alkaline protease. The neutral protease has a molecular weight of about 44,000 and contains from 1 to 2 atoms of zinc per molecule. It also exhibits amylolytic activity. Its particle size ranges predominantly from 0.03 mm. to 0.1 mm. and can be prepared to range in active enzyme content from 20% to 75%. This enzyme can be utilized in the composition of this invention with excellent results.

Pronase-P, Pronase-E, Pronase-AS and Pronase-AF are powdered enzyme products which can also be used to advantage in this invention. These enzymes are produced from the culture broth of Streptomyces griseus used for streptomycin manufacture. They are isolated by the successive resin column treatment. A major component of the pronase is a neutral protease named as Streptomyces griseus protease. This enzyme product is useful herein and provides excellent soiland stain-removing properties.

Another enzyme product preferred for use in the detergent compositions of this invention, as illustrated in the Examples below, is a proteolytic enzyme, a serine protease, manufactured by Novo Industri A/ S, Copenhagen, Denmark, and sold under the trade name of Alcalase. Alcalase is described, in a trade bulletin bearing that name which was published by Novo Industri A/S, as a proteolytic enzyme preparation manufactured by submerged fermentation of a special strain of Bacillus subtilz's. The primary enzyme component of Alcalase is subtilisin. Alcalase is a fine grayish, free-flowing powder having a crystalline active enzyme content of about 6% and a particle size ranging from 1.2 mm. to .01 mm. and smaller, about 75% passing through a 150 mesh Tyler screen. The remainder of the powder is comprised primarily of sodium sulfate, calcium sulfate and various inert organic vehicle materials. Alcalase can be advantageously used with the synthetic detergent compositions of this invention.

The phosphorous-containing compounds which are essential components of the compositions of the present invention are sequestrant compounds characterized by the capacity to sequester calcium ions from aqueous solution.

The phosphorus-containing sequestrants useful herein are those having sufiicient calcium sequestration properties to reduce the wlcium ion concentration of an aqueous solution containing 1.2. M of calcium ion to a concentration of 1.7 1O M or less when employed in an amount of up to 0.1% of the solution.

The sequestration capacity of the phosphorus-containing compounds useful herein can be determined conveniently by detecting the amount of calcium ion remaining in aqueous solution following the addition of a phosphorus-contaiuing sequestrant of the invention. The level of calcium ion in an aqueous solution can be determined by a calcium electrode which operates by developing an electrical potential across a thin layer of water-immiscible liquid ion exchanger. This liquid is held mechanically rigid by a thin porous inert membrane disc. The liquid ion exchanger, a calcium salt of an organophosphoric acid, exhibits a very high specificity for calcium ions. An internal filling solution of calcium chloride contacts the inside surface of the membrane disc. The calcium ion in this solution provides a stable potential between the inside of the membrane and the filling solution, while the chloride ion provides a stable potential between a silver-silver chloride internal reference electrode and the filling solution. Thus, changes in potential are due only to changes in sample calcium ion activity.

The electrode responds only to the ionized or unbound calcium in the sample. The electrode does not respond to that portion of the calcium which is bound to a sample of phosphorus-containing sequestrant of the invention. The calcium concentration can -'be determined by detection of the electrode potential and comparison with a calibration curve of calcium ion concentration and electrode potential.

The calcium sequestering capacity of the phosphoruscontaining compounds of the invention is measured by adding increments of a solution of the compound, preferably as an acid or potassium salt form, to a l.2 10 M calcium chloride solution over a period of one hour at a temperature of 25 C. The electrical potential is measured with each incremental addition, the additions being continued until no further sequestration decrease in calcium ion concentration is detected or until the concentration of added sequestrant is 0.1% of the solution. Phosphoruscontaining sequestrants useful herein reduce calcium ion concentration, under the conditions of this test, to 1.7 10- M or less when employed at a concentration of up to 0.1%. Preferred compounds herein reduce the concentration to 1.7 10- M or less by the addition of from 0.03 to 0.06%.

A suitable calcium electrode for measuring calcium ion concentration and sequestration capacity of the polycarboxylates of the invention is available as model 92-20 from Orion Research Incorporated, (11 Blackstone St., Cambridge, Mass.).

Suitable phosphorus-containing sequestrants of the invention include the alkali metal tripolyphosphates, alkali metal pyrophosphates, ethane-1,1-diphosphonic acid and water-soluble salts thereof, ethanehydroxy-l,1,2-triphosphonic acids and water-soluble salts thereof and condensates of ethane-l-hydroxy 1,1 diphosphonic acid and water-soluble salts thereof.

Specific examples of suitable alkali metal tripolyphosphates and pyrophosphates include sodium tripolyphosphate, potassium tripolyphosphate, sodium pyrophosphate and potassium pyrophosphate. Preferred herein is sodium tripolyphosphate. This salt is especially valuable herein in its anhydrous or partially hydrated form and acts as a moisture sink of dissicant and thus controls, to some extent, free moisture in a detergent composition. It is preferred, therefore, that the sodium tripolyphosphate be employed herein in its anhydrous or partially hydrated form.

Also suitable herein are ethane-1-hydroxy-l,l-diphosphonic acid and water-soluble salts thereof having the following formula cs d on I 20 14 wherein each M is hydrogen or a salt-forming or watersolubilizing cation. Suitable cations include the alkali metal, ammonium and substituted-ammonium cations.

In the preceding formula, suitable alkali metals are sodium, potassium and lithium. Illustrative examples of substituted-ammonium cations are monomethylammonium, diethylammonium, tripropylammonium, tetrabutylammonium, hydroxymethylammonium, hydroxyethylammonium, 2 hydroxypropylammonium and 2 hydroxybutylammonium. The acid and salt forms are collectively termed herein ethane-l-hydroxy-1,1-diphosphonates.

The most readily crystallizable form of ethane-l-hydroxy-1,l-diphosphonic acid is obtained when three of the acid hydrogens are replaced by sodium. Hence, the salt commonly prepared is the trisodium salt, which gives a pH nearly 9.5 in distilled water. The anhydrous trisodium salt has the structure -3 P03 I c11 c on Na It crystallizes normally as the hexahydrate, which loses some water during air-drying to yield a mixture of the hexaand monohydrate averaging 3 to 4 molecules of water of hydration.

Suitable herein are the ethanehydroxy-l,1,2-triphosphonic acids and water-soluble derivatives thereof having the formula 70 14 fe r r x c c Y I I 11 P031142 T094 PC3142 H C c on Formula I as well as those having the formula 70 14 1|O M HO C C H l H PC 14 Formula II wherein each M is as hereinbefore defined.

The compounds depicted by Formula I, above, are named ethane-1-hydroxy-1,l,2-triphosphonates. The acid represented by this formula is ethane-1-hydroxy-1,1,2-triphosphonic acid. Specific examples of compounds falling within the contemplation of Formula I are trisodium trihydrogen ethane-l-hydroxy-1,1,2-triphosphonate; tetrasodium dihydrogen ethane 1 hydroxy-1,1,2-triphosphonate, pentasodium monohydrogen ethane-1-hydroxy-l,1,2- triphosphonate, and hexasodium ethane-1-hydroxy-1,1,2- triphosphonate. The corresponding alkali metal salts such as potassium and lithium can be prepared and also fall within the scope of the present invention.

The compounds depicted by Formula II, above, are named ethane-Z-hydroxy-l,1,2-triphosphonates. The acid represented by this formula is ethane-2-hydroxy-1,l,2- triphosphonic acid. Specific examples of compounds falling within the contemplation of Formula II are trisodium trihydrogen ethane-2-hydroxy-l,l,Z-triphosphonate; tetrasodium dihydrogen ethane-Z-hydroxy-l,1,2-triphosphonate; pentasodium monohydrogen ethane-Z-hydroxy- 1,1,2-triphosphonate; hexasodium ethane-2-hydroxy-1,1,2- triphosphonate.

The ethanehydroxy-l,1,2-triphosphonates useful herein are known compounds. Examples and methods for their preparation are described more fully in US. Pat. 3,400,- 148 to Oscar T. Quimby, issued Sept. 3, 1968, and incorporated herein by reference.

Another class of phosphorus-containing sequestrants useful herein are the oligomeric ester chain condensates of ethane-l-hydroxy-l,l-diphosphonic acid and salts thereof having the formula 14 wherein M is hydrogen or a water-solubilizing cation defined hereinbefore; R is hydrogen or acetyl and n has a numerical value in the range of 1 to about 16.

The oligomeric ester chain condensates of ethane-1- hydroxy-1,1-diphosphonic acid and salts thereof are characterized by the presence of C-O-P bonds and comprise a mixture of condensates having different chain lengths Within the range of from 1 to 16 given above for n. Preferably n ranges from 2 to 12. The molecular weights of these compounds are in the range of from about 500 to about 4000 calculated as the sodium salts. Within the preferred range, the molecular weights are within a range of about 700 to about 3000. These values are related to the numerical values of n presented above.

Examples of suitable oligomeric condensates include the sodium salts of an oligomeric ester chain condensate of ethane-l-hydroxy-l,l-diphosphonic acid having an average molecular weight of 1000-3000 and the sodium salt of an oligomeric ester chain condensate of ethane-lhydroxy-l,l-diphosphonic acid having an average molecular Weight of 500-1600. The oligomeric ester chain condensates of the present invention and methods for their preparation are described in US. patent application Ser. No. 786,371 of James B. Prentice, entitled Oligomeric Ester Chain Condensates of Ethane-l-hydroxy-1,1-diphosphonic Acid, filed Dec. 23, 1968 and incorporated herein by reference.

The phosphorus-containing sequestrants useful herein are employed in an amount corresponding to a ratio of organic detergent to phosphorus-containing compound of from about 2:1 to about 1:10. Preferably, the ratio is from about 1:1 to about 1:3. The precise manner in which these components function to enhance cleaning levels is not completely understood. While the compounds are termed sequestrants herein, the function of these materials in the compositions of the invention is not known with precision. Surprising cleaning effects are observed in spite of the tendency of many sequestrants to decline markedly in sequestering capacity as pH varies from 10 to 6. It is believed that phenomena in addition to sequestration are inevitably involved.

The advantages of neutral laundry washing, hereinbefore described, are attained herein by formulating the compositions of the invention to have a pH in distilled water of from 6 to 8.5. While alkaline components can be used herein, their use will normally require the incorporation of one or more additional components to ensure the provision of detergent compositions having a substantially neutral pH.

For example, ethane-l-hydroxy-l,1-diphosphonic acid or any alkali metal or ammonium or substituted-ammonium salt form can be used as the phosphorus-containing compound in this invention. Preferred forms include the free acid and the lesser neutralized forms such as the monosodium and disodium derivatives. These forms are preferred from the standpoint of facilitating the preparation of detergent compositions having a substantially neutral pH in aqueous solution. The tetrasodium salt, the trisodium salt and mixtures thereof which give a pH in aqueous solution of from about 9.5 to 11.5, while suitable herein, will normally require the addition of a pH adjuster to ensure the provision of a detergent composition providing a pH of from about 6 to 8.5 in solution as hereinbefore described.

The employment of a pH adjuster and the amounts utilized will depend upon the pH of the composition. For example, when an alkaline ethane-1-hydroxy-1,1-diphosphonate component is utilized herein, an acidic compound such as sulfuric acid or sodium bisulfate will normally be employed to ensure the provision of washing solutions having the hereinbefore specified substantially neutral pH. Similarly, when an acidic derivative is employed herein, an alkaline pH adjuster such as sodium hydroxide will be employed to adjust to a substantially neutral pH. The amount of pH adjuster employed in the enzyme-containthis reason are the aminopolycarboxylates which provide a pH of about 6. Nitrilotriacetic acid and the sodium salts such as N32 nitrilotriacetate and Na nitrilotriacetate are preferred.

The enzyme-containing detergent compositions of this invention can be prepared by methods known to those skilled in the art and can be prepared in any suitable physical form such as granules (e.g., either spray-dried or mechanically mixed), flakes, tablets, pastes, or liquids. For example, a mixture of organic detergent and phosphorus-containing compound utilizable herein can be employed in the form of spray-dried or agglomerated granules or in the form of a mechanical mixture of granular organic detergent and phosphorus-containing compound. Detergent granules can range in size from about 100% through a Tyler standard 6-mesh screen (3.33 mm.) to about 100% on a Tyler standard 200- mesh screen (0.074 mm.). Segregation of granules in the detergent composition is minimized when the particle size of the granules ranges from about 100% through a Tyler standard 12 mesh screen (1.4 mm.) to about 100% on a Tyler standard 100 mesh screen (0.15 mm.); this latter particle size range is preferred. The bulk density of the detergent granules, in order to reduce segregation, preferably ranges from about 0.2 gm./cc. to about 0.8 gm./cc.

A mixture of detergent and phosphorusmontaining compounds or granules thereof can be mechanically admixed with a proteolytic enzyme described hereinbe-fore to provide detergent compositions having the advantageous cleaning and soiland stain-removing properties hereinbefore described.

It is normally preferred that the proteolytic enzyme hereinbefore described be present in the detergent compositions of the present invention in such a manner as to minimize segregation of the enzyme and enhance the soiland stain-removing properties of the enzyme employed. For example, the enzyme can *be mixed with water into a slurry and sprayed onto one or more granular components comprising the detergent compositions of this invention and which serve as granular carriers for the enzymatic material. Especially suitable is the application of an aqueous enzyme slurry by spraying onto granules comprising the organic detergent and phosphorus-containing compound, e.g., anhydrous sodium tripolyphosphate. The resulting enzyme-containing granules can be employed as pre-soak or laundry washing compositions per se or can be admixed with any remaining components of the compositions of the invention.

In a finished detergent formulation of this invention there will often be added in minor amounts materials which make the product more effective or more attractive. The following are mentioned by way of example. Soluble sodium carboxymethylcellulose can be added in minor amounts to inhibit soil redeposition. A tarnish inhibitor such as benzotriazole or ethylenethiourea can also be added in amounts up to about 2%. Fluorescers, perfume and color, while not essential in the compositions of the invention, can be added in amounts up to about 1%. Minor amounts of bufiering agents, such as borates, orthophosphates or carbonates, can be added to maintain substantially neutral the pH of washing solutions of the finished compositions. 'Enzyme stabilizers can be employed to maintain enzymatic activity. Inert electrolytes such as 16 sodium sulfate can be employed and are often utilized as fillers. There might also be mentioned as suitable additives, water, other enzymes such as amylases and other hydrolytic enzymes; brightening agents and bleaching agents such as sodium perborate.

The behavior and mechanism by which the detergent, enzyme and phosphorus-containing components of the present invention operate to provide unexpectedly high levels of cleaning under substantially neutral pH conditions is not completely understood. Unequivocal criteria and principles do not exist which would permit one to predict which components in combination would possess the levels of cleaning exhibited by the compositions of the invention. The sodium salts of linear alkylbenzenesulfonate or tallow alkyl sulfate, for example, are excellent detergent materials believed to be more efiicient cleaners than ethoxylated tallow alkyl sulfates. Compositions of the invention embodying an ethoxylated alkyl sulfate, sodium tripolyphosphate and a proteolytic enzyme pro vide higher levels of cleaning at pH 7 than compositions containing the sodium salt of a linear alkylbenzenesulfonate or tallow alkyl sulfate in place of the ethoxylated alkyl sulfate. The superior cleaning effect observed is obtained even though the sequestering capacity of sodium tripolyphosphate is observed to fall off below pH 9. Moreover, compositions of the invention are more effective under substantially neutral conditions of pH than conventional alkaline, phosphate-built linear alkylbenzenesulfonate-containing compositions.

The compositions of the present invention can be employed as pre-soak compositions to remove soils and stains prior to a separate laundering step or can be employed as a laundering product according to conventional laundering methods. While the compositions of the invention are especially suited for the laundering of textile materials, they can be employed as cleansing compositions in the washing of dishes, pots and pans, other hard surfaces such as walls and floors and the like.

The following examples serve to illustrate but not limit the novel compositions of the present invention. All amounts in the examples are in parts :by weight except as otherwise indicated.

EXAMPLE I Spray-dried detergent granules having the following formulation were prepared.

Component: Parts by wt.

Sodium salt of olefin sulfonate derived from l-hexadecene 25 Sodium tripolyphosphate 17.5 Disodium nitrilotriacetate 17.5

Sodium sulfate 29 Water 10 Miscellaneous (brighteners, sodium carboxymethyloellulose) 1 Total These detergent granules had particle sizes ranging from 0.074 mm. to 1.41 mm. and a density of about 0.3 gms./ cc. The granules had a pH in aqueous solution of 8.0. One hundred parts of the spray-dried detergent granules were mechanically mixed with 0.05 part of Alcalase (6% subtilisins in a powdered vehicle). The resulting enzyme-containing detergent compositions had a pH of 8.0 in aqueous solution and exhibits excellent cleaning and soiland stain-removing properties under neutral conditions of pH.

EXAMPLE II Detergent granules spray-dried from a crutcher mix adjusted to pH 7.5 with sulfuric acid and having the following formulation are prepared.

These detergent granules have particle sizes ranging from 3.33 mm. to 0.074 mm. and a density of about 0.5 gms./cc.

A slurry containing 1.00 part water and 0.53 part Alcalase (contains 6% active, alkaline Carlsberg subtilisinremainder is inert materials such as sodium and calcium sulfate) is prepared. This slurry is sprayed onto 5.10 parts of granular, anhydrous sodium tripolyphosphate (adjusted to pH 7.5 with sulfuric acid) and these protease-containing granules are mixed uniformly with the above described mixture of spray-dried detergent granules.

This detergent composition provides a pH of 7.5 in aqueous solution and is an excellent laundering composition exhibiting soiland stain-degrading properties.

Similar results can be obtained when the sodium salt of C olefin sulfonate is replaced wholly or in part with a sodium salt of an ethoxylated tallow-alkyl sulfate having an average of from 3 to 6 ethoxylate groups.

EXAMPLE III Detergent granules spray-dried from a crutcher mix adjusted to pH 7 with sulfuric acid and having the following formulation are prepared.

These detergent granules have particle sizes ranging from 3.33 mm. to 0.074 mm. and a density of about gms./ cc. Five parts of Monsanto DA-l0 (20 to 25% mixture of 80:20 neutral and alkaline subtilisins in powdered vehicle) are mechanically admixed with these granules. The resulting detergent composition provides excellent cleaning and soiland stain-removing properties.

EXAMPLE IV Detergent granules spray-dried from a crutcher mix adjusted to pH 7 with sulfuric acid and having the following formulation are prepared.

Component: Parts by wt. Sodium salt of ethoxylated tallow-alkyl sulfate (average of 6 ethoxylate groups) 25 Disodium ethane-l-hydroxy-l,l-diphosphonate 30 Sodium sulfate 33 Water 10 Miscellaneous (perfume, brighteners, sodium carboxymethylcellulose) 2 Total 100 These detergent granules have particle sizes ranging from 3.33 mm. to 0.074 mm. and a denisty of about 0.5 gm./ cc. Five parts of Monsanto -DA-10 (20 to 25% mixture of 80:20 neutral and alkaline subtilisins in powdered vehicle) are mechanically admixed with these granules. The

18 resulting detergent composition provides excellent cleaning and soiland stain-removing properties.

EXAMPLE V An excellent detergent composition giving outstanding cleaning results in substantially neutral laundering solutions has the following composition in the parts by Weight indicated.

Component: Parts by wt. Sodium salt of the methyl ester of a-sulfonated tallow fatty acid 30 Trisodium ethane-l-hydroxy 1,1,2 triphosphonate 25 Sodium sulfate 30 Borax 10 Water 5 Mixture of about 20 to 25 :20 neutral and alkaline subtilisins in powdered vehicle (Monsanto DA-lO) 0.8

Substantially similar results can be obtained when the sodium salt of the methyl ester of a-sulfonated tallow fatty acid is replaced by the sodium, potassium and lithium salts of the methyl, ethyl, propyl, butyl, hexyl and octyl esters of a-sulfonated lauric, myristic, palmitic, stearic, palmitoleic, oleic and linoleic acids; the ammonium, dimethylammonium, tetramethylammonium, dimethyl, piperdinium and diethanolamine salts of the methyl, ethyl, propyl, butyl, hexyl and octyl esters of a-sulfonated lauric, myristic, palmitic, stearic, palmitoleic, oleic and linoleic acids.

The sodium tripolyphosphate compound of Example I can be replaced by potassium tripolyphosphate in whole or in part with equally good results.

EXAMPLE VI Another excellent detergent composition for use at substantially neutral pH in typical household laundering apphcations has the following ingredients.

Component: Parts by wt. Sodium fl-acetoxy-hexadecane-l-sulfonate 25 Sodium pyrophosphate 50 Sodium bisulfate 20 Sodium chloride 5 Mixture of 6% Carlsberg subtilisin in powdered vehicle (Alcalase) 0.8

Substantially similar results can be obtained when the following fl-acyloxy-alkane-l-sulfonates are employed in lieu of sodium jS-acetoxy-hcxadecane-l-sulfonate: the sodium salt of 2-acetoxy-tridecane-l-sulfonic acid; the potassium salt of 2-propionyloxy-tetradecane 1 sulfonic acid; the lithium salt of Z-butanoyloxy-tetradecane-l-sulfonic acid; the sodium salt of Z-pentanoyloxy-pentadecane-l-sulfonic acid; the ammonium salt of 2-hexanoyloxyhexadecane-l-sulfonic acid; the dimethylammonium salt of 2-heptanoyloxytridecane-l-sulfonic acid; the potassium salt of 2-octanoyloxytetradecane-l-sulfonic acid; the dimethy-lpiperdinium salt of 2-nonanoyloxytetradecane-1- sulfonic acid; the sodium salt of 2-acetoxy-heptadecanel-sulfonic acid; the lithium salt of Z-acetoxy-octadecanel-sul'fonic acid; the dimethylamine salt of 2-acetoxyoctadecane-l-sulfonic acid; the potassium salt of 2-acetoxynonadecane-l-sulfonic acid; the sodium salt of 2-acetoxyuncosane-l-sulfonic acid; the sodium salt of 2-propionyloxy-docosane-l-sulfonic acid; and isomers thereof.

EXAMPLE VII Excellent cleaning results are obtained in substantially neutral washing solutions using a detergent composition prepared according to this invention and having the following ingredients.

19 Component: Parts by wt. Sodium tallow-alkyl hexaoxyethylene sulfate 25 Disodium ethane-l-hydroxy-l,l-diphosphonate 40 Substantially similar results can be obtained when the following enzymes are employed in lieu of Pronase E: Alcalase, Novo Industri, Copenhagen Denmark; Maxatase, Koninkliike Nederlandsche Gist-En Spiritusfabriek N.V., Delft, Netherlands; Protease B-4000 and Protease AP, Schweizerische Ferment A.G., Basel, Switzerland; CRD-Protease, Monsanto Company, St. Louis, Mo.; Violrase, VioBin Corporation, Monticello, 111.; Pronase-P, Pronase-AS and Pronase-AF all of which are manfactured by Kaken Chemical Company, Japan, Rapidase P-2000, Rapidase, Seclin, France; Takamine, HT proteolytic enzyme 200, Enzyme L-W (derived from fungi rather than bacteria), Miles Chemical Company, Elkhart, Ind.; Rhozyme P-11 concentrate, Rhozyme PF, Rhozyme J-25, Rohm & Haas, Philadelphia, -Pa.; Rhozyme PF and J-25 have salt and corn starch vehicles and are proteases having diastase activity; Amprozyme 200, Jacques Wolf & Company, a subsidiary of Nopco Chemical Company, Newark, N.J.; Takeda Fungal Alkaline Protease, Takeda Chemical Industries, Ltd., Osaka, Japan; Wallerstein 201-HA, Wallerstein Company, Staten Island, NY; 'Protin AS-ZO, Dawai Kasei K.K., Osaka, Japan; and Protease TP (derived from thermophilic Streptomyces species strain 1689), Central Research Institute of Kikkoman Shoya, Neda Chiba, Japan.

Similar results can be obtained when the disodium ethane l-hydroxy-l-diphosphonate is replaced by the sodium salt of an oligomeric ester chain condensate of ethane-Lhydroxy-1,1-diphosphonic acid having an average molecular weight of 1000-3000 or the sodium salt of an oligomeric ester chain condensate of ethane-l-hydroxy- ,l,1-diphosphonic acid having an average molecular weight of 500-1600 in that desirable cleaning effects are observed.

EXAMPLE VIII An effective cleaning detergent composition of the present invention when employed in a neutral laundering solution has the following composition.

Component: Parts by wt. Sodium salt of sulfonated l-hexadecene 30 Trisodium ethane 1 hydroxy-1,l,2-triphosphonate 30 Sodium sulfate Borax 15 Enzyme mixture of about 20 to 25% 80:20 neutral and alkaline subtilisins in powdered vehicle (Monsanto DA-IO) 0.7

Substantially similar results are obtained when the following olefin sulfonates are employed in lieu of the sodium salt of sulfonated l-hexadecene: the sodium, potassium, lithium and ammonium salts of sulfonated l-dodecene, 1- tetradecene, l-octadecene, l-eicosene and l-tetracosene.

EXAMPLE IX An effective and efiicient detergent composition useful in substantially neutral washing solutions according to this invention has the following composition:

Similar results are obtained when the following phosphine oxide detergents are substituted for the dimethyldodecylphosphine oxide: tetradecyldimethylphosphine oxide; tetradecylmethylethylphosphine oxide; 3,6,9-trioxaoctadecyldimethylphosphine oxide; cetyldimethylphosphine oxide; 3 dodecoxy-2-hydroxypropyldi(2-hydroxyethyl)phosphine; stearyldimethylphosphine oxide; cetylethylpropylphosphine oxide.

EXAMPLE X Superior cleaning effects are obtainable in neutral washing solutions with a detergent composition having the following ingredients:

Component: Parts by wt. Sodium-Z-hexadecylmethylaminopropionate 25 Disodium pyrophosphate 40 Sodium chloride 15 Sodium bicarbonate 20 6% Carlsberg subtilisin in powdered vehicle (Alcalase) 0.5

Substantially similar results can be obtained when the following ampholytic detergents are employed in lieu of the sodium hexadecylmethylaminopropionate: sodium 3 dodecylarninopropanesulfonate; sodium 3-dodecylaminopropionate; N-dodecyl-taurines; and N-dodecyl asparate.

EXAMPLE XI An effective and eificient detergent composition useful in substantially neutral washing solutions according to this invention has the following composition:

Component: Parts by wt. Dimethyldodecylphosphine oxide 30 Sodium tripolyphosphate 30 Sodium bisulfate 10 Sodium chloride 30 6% Carlsberg subtilisin in powdered vehicle (Alcalase) 1 Similar results are obtained when the following phosphine oxide detergents are substituted for the dimethyldodecylphosphine oxide: tetradecyldimethylphosphine oxide; tetradecylmethylmethylphosphine oxide; 3,6,9-tn'- oxaoctadecyldimethylphosphine oxide; cetyldimethylphosphine oxide; 3 dodeooxy-Z-hydroxypropyldi(Z-hydroxyethyl)phosphine; stearyldimethylphosphine oxide; cetylethylpropylphosphine oxide.

EXAMPLE XII A superior detergent composition effective in the cleaning of textile fabrics under neutral conditions has the following composition:

Mixture of about 50% :20 neutral and alkaline protease in powdered vehicle (Pronase- E) -1 0.8

21 Substantially similar results can be obtained when the dimethylhexadecylammoniopropanesulfonate is replaced with:

4- [N,N-di (Z-hydroxyethyl )-N-octadecylammonio] butanel-carboxylate;

- [S- 3-hydroxypropyl) -S-hexadecylsulfonio] -3-hydroxypentane-l-sulfate;

3- [P,P-diethyl-P- 3,6,9-trioxatetracosanephosphonio) 1- 2-hydroxypropanel-phosphate;

3- [N,N-dipropyl-N 3-dodecoxy-Z-hydroxypropylammonio) ]-propane-1-phosphonate;

N,N-dimethyl-N-hexadecylammonioacetate;

3- (N,N-dimethyl-N-hexadecylammonio -2-hydroxypropanel-sulfonate;

4- [N,N-di(2-hydroxyethyl) -N-(2-hydroxydodecylammonio) ]-butane-1-carboxylate;

3- [S-ethyl-S-( 3-dodecoxy-2-hydroxypropylsulfonio) propanel-phosphate;

3- [P,Pdimethyl-P-dodecylphosphonio] -propane-1- phosphonate; and

5 [N,N-di( 3-hydroxypropyl) -N-hexadecyclammonio] 2-hydroxypentane-l-sulfate.

Wash-wear tests using standardized detergent compositions described below were performed to illustrate the relative effectiveness of representative compositions of the present invention. A sodium tripolyphosphtae-built anionic active-containing formulation was used as a standard basis of comparison in these tests due to its current wide use in the industry. In addition, compositions corresponding to those of the present invention but containing no enzymes were evaluated. The results of these tests presented in Table 1 conclusively show the outstanding performance advantages of the detergent compositions prepared according to this invention.

The wash-wear tests involving washing ntaurally soiled white dress shirts in the following manner. Shirts carrying detachable collars and cuffs were worn by male subjects under ordinary conditions for two normal working days. Following wearing, the collars and cuffs were washed for ten minutes in a small agitator type machine using solutions of the detergent compositions to be evaluated. These washing solutions were prepared by adding to water of 7 grain hardness the various components of the compositions to be evaluated in the desired amounts. The washing conditions were as hereinafter specified in Table 1. After four washing and drying cycles, the collars and cuffs washed by a composition being evaluated were visually compared with similarly soiled collars and cuffs which were washed in the standard detergent composition under substantially the same conditions. The visual comparison was made by a group of five people who were unfamiliar with the procedure and purpose of the test and formed their judgment independently.

The data from the visual judgments are expressed on a scale such that a value of 0 represents the cleaning ability of water alone and a value of 10 represents the cleaning ability of a very excellent detergent composition used under optimum laboratory conditions along with an effective bleanching agent. On this scale, a value of about 6.5 represents good, better than average, cleaning, while a value of 3.5 represents unsatisfactory cleaning. The primary purpose of these determinations and this type of grading scheme was to establish the relative cleaning performance of several compositions of this invention as compared to a commercially acceptable type of formula employing a linear alkylbenzenesulfonate detergent and a sodium tripolyphosphate builder. The components and amounts of the materials employed in the washing solutions used in these white shirt detergency tests are indi cated in Table 1. In each instance sodium hydroxide was employed to adjust the pH to the stated value. No fluo rescers, bleaches or anti-redeposition agents were employed, except where otherwise indicated, so as not to mask the cleaning effect of the compositions of the present invention. The washing solutions in each instance were standardized to the pHs indicated in Table 1 and in all instances the water used contained 7 grains per gallon of hardness. The temperatures of the washing solutions were indicated in Table 1. The sodium linear alkylbenzenesulfonate employed as the anionic active in the standardized detergent composition had an alkyl chain distribution averaging about 11.8.

This linear alkylbenzenesulfonate is indicated in Tables 0.05% sodium ,B-acetoxyhexadecane 1 sulfonate; 0.05% sodium pyrophosphate; pH 7; F.; 10 p.p.m. Monsanto DA-IO enzyme 9.4

0.05% sodium fi-acetoxyhexadecane 1 sulfonate;

0.04% sodium ethane 1 hydroxy-l,l,2-triphosphonate; pH 7, 120 F.; 10 p.p.m. Monsanto DA- 10 enzyme 8.0

For purposes of comparison with detergent compositions of the present invention the above described washwear test was repeated employing a sodium linear alkylbenzenesulfonate described hereinbefore and sodium tallow-alkyl sulfate as the detergent actives. Sodium tripolyphosphate, sodium polymaleate or citric acid was added as specified in Table 2 which describes the results of these tests.

TABLE 2.-COMPARATIVE TESTS (Solution concentrations) 0.05% LAS; 0.06; sodium tripolyphosphate; pH 7; 120 F.; 10 p.p.m. Monsanto RA-lO enzyme 0.05% LAS; 0.03% sodium polymaleate; pH 7.5; 120 F.; 10 p.p.m. Alcalase 0.05% sodium tallow-alkyl sulfate; 0.04 citric acid;

pH 7; 120 F.; 5 p.p.m. Pronase-E 4.8

The results of Table 1 illustrate the superior cleaning properties of compositions of the present invention and illustrate the efficacy of each of these compositions as compared with a standard alkaline built formulation commonly employed in the detergency industry and with a composition corresponding to those of the invention, but containing no enzymes. The results indicated in Table 2 illustrate the cleaning effects of compositions containing certain anionic surfactants, builders and enzymes. These compositions fail to equal in cleaning performance the hereinbefore described standard composition or those of the present invention.

Having described the invention in detail, what is claimed is:

1. A substantiallyneutral, laundry detergent composition consisting essentially of:

(A) from 10% to 85% of a synthetic organic detergent selected from the group consisting of:

(1) compounds of the formula a o I II R -C-c-OR se m wherein R is alkyl or alkenyl of about 6 to about 20 carbon atoms, R is alkyl of 1 to about 10 carbon atoms, and M is a salt-forming cation; and

(2) compound of the formula R CH CH SO M wherein R is alkyl of about 9 to about 23 carbon atoms, R: is alkyl of 1 to about 8 carbon atoms, and M is a salt-forming cation;

(B) from 0.001% to of a proteolytic enzyme having proteolytic activity up to about 130 F. in the pH range of from 6 to 8.5; and

(C) from to 75% of a phosphorus-containing sequestrant compound having suflicient calcium sequestration properties to reduce the calcium ion concentration of an aqueous solution containing 1.2X10 M of calcium ion to a concentration of 1.7 l0 M or less when employed in an amount of up to 0.1% of the solution, said compound being selected from the group consisting of alkali metal tripolyphosphates and alkali metal pyrophosphates.

2. The composition of claim 1 wherein the synthetic organic detergent is a compound of the formula wherein R is alkyl or alkenyl of about 6 to about 20 carbon atoms, R, is alkyl of l to about 10 carbon atoms and M is a salt-forming radical; and is employed in an amount of from to 50%.

3. The composition of claim 1 wherein the proteolytic enzyme is a bacterial, or fungal or mold protease.

4. The composition of claim 3 wherein the proteolytic enzyme is employed as a powdered composition comprising from 2% to 80% protease and from to 98% of an insert powdered filler material selected from inorganic alkali metal salts; inorganic alkaline earth metal salts, non-enzymatic proteins; carbohydrates, organic clays; starches; lipids; and mixtures thereof; and the powdered composition is employed in an amount of from 0.03% to 10%.

5. The composition of claim 1 wherein the synthetic organic detergent is a compound of the formula OCR wherein R is alkyl of about 9 to about 23 carbon atoms, R, is alkyl of 1 to about 8 carbon atoms and M is a salt-forming radical; and is employed in an amount of from l5% to 5 0%.

6. The composition of claim 5 wherein the synthetic organic detergent is a compound of the formula OCR R CH CH SO M UNITED STATES PATENTS 2,094,451 9/1937 Guenther et al 260-9912 3,274,117 9/1966 Stein et al 252-461 3,413,221 11/1968 Gotte et al. 252-438 3,451,935 6/1969 Roald et al 252-- 3,519,570 7/1970 McCarty et a1. 252-135 FOREIGN PATENTS 6715387 5/ 1968 Netherlands 252-Enz. Dig.

OTHER REFERENCES Hoogerheide, J. C., et al.: The Development of Biological Cleaning Compounds, Kemian Teollisuus, vol. III, 1967, pp. 207212, 221.

LEON D. ROSDOL, Primary Examiner P. B. WILLIS, Assistant Examiner US. Cl. X.R.

UNITED STATES "PATENT @FFKCE CERTIFICATE 0F CURREGTION Patent No. 3'658'727 Em a April 25, 19 72 Inventor(s) Roy Mast It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 6, line 58 "cabroxy" should vread "carboxy.

Column 8, line 68, "enzyme" should read "enzyme". Column 9, line 28, "tyrosin" should read "tyrosine".

Column 9. line 41, "protrease" should protease. A

Column 20, line 44, "tetradecylmethylmethylphosphine" should read "tetradecylmethylethylphosphine,.

Column 21, line 27, "tripolyphosphtae" should read "tripolyphosphate".

Column 21, line 36, "ntaurally" should "naturally". Column 21, line 60, 'bleanching should read "bleaching".

Column 22, line 23, "0.60%"should "0,06%"

Column 22, line 56 RA" should read "DAM Column 24, line 28, "insert" should read "inert" Signed and sealed this 19th day of September 1972.,

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK J 'mztesting Officer Commissioner of Patents 

